Process of grinding piston-rings.



PATENTED SEPT. 18,1906.

P. GARTH.

PROCESS OF GRINDING PISTON RINGS.

APPLICATION IILILD NOV. 14, 1905.

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' other reasons.

UNITE STATES PATENT oFFIonj Specification of Letters Patent.

Application filed November 14,1905. Serial No. 287,292.

To-aZZ whom, it may concern.-

Be it known that I, PAUL GAETH, a citizen of the United States, residingat Cleveland, in the county of Cuyahoga and State of Ohio, have inventednew and useful Improvements in Processes of Grinding Piston-Rings, ofwhich the following is-a specification.

This invention is a process of grinding and fitting pistons and pistonpacking-rings.

In the existing state of the industry the piston and rings are groundseparately, the ringsbeing ound before they are placed in postion on t episton. cause the best fit is not. obtained and for By means of thepresent invention the piston and rings are ground at the same time andwhile the latter are in position. means must be provided to'hold t emout flush or in proper position during the grinding operation. This isdone by running in some readily-fusible substance under or behind therings, which when it solidifies holds centering the rings on the piston.

grinding implement.

the rings in place. and prevents them from yielding inwardly under thepressure of the Said substance is afterward melted out, and the ringsare left in place at a true and correct fit.

The invention is illustrated in the accompanying drawings, Figure 1being a sectional elevation showing the manner of locating and Fig. 2 isa section of the piston, showing the rings in position and the means forintroducing the fusible substance behind the same.

Primarily the piston and ringsare turned to the size wanted plus theallowance for grinding. The rings, which are indicated at 6, are thenslipped in position in their grooves in the piston, so tlfat all thelaps7 come in a straight line down the side of the iston. The sleeve 8 isthen slipped over t e piston, thus centering the rin s in lace on thepiston. Holes are then ille lengthwise through the walls of the iston 9and through the ends of the rin s a jacent to the lap to receive wires10, w 'ch thus hold the rings and prevent them from turning or spreadingapart during the grinding operation. After this is done the piston,which,as shown, is of the trunk type, is turned upside down and filledwith a readily-fusible substance, such as wax, and this is heated,causing the substance to. run through the holes 11 into the spaces 12 inthe grooves under the rings.

This is defective, be

Since the rings yield-under ressure,

cooled and the fusible substance solidified.

Patented Sept. 18,1906. I

Now the piston and its rings are ready for grinding and can be groundand polished by any of the approved machines or means for that purpose.The rings are held against ro-,

tation and also against yielding inwardly and are so acted upon by thegrinding instruments the same as the piston'and are ground to the truesurface and accurate diameter desired. After the piston and rings areground to size and finish the piston is reheated and the readily-fusiblesubstance is run out. The

wires 10 are then withdrawn and the holes in which they were containedare plugged up. Pins are also put into the holes 11.

The process is not confined to a piston or its rings nor to theparticular type of piston shown for the purpose of illustration, butmay; be applied to .any analogous device where a yielding acking-ring orsurface is to be ground or po ished in connection with a relativelyrigid p'art or surface. The method described saves the labor of twoseparate operations upon the respective parts and also insures a-betterfit and more correct size.

I claim; 7 4

1. The method of grinding. simultaneously a relatively rigid part and arelatively yielding part carried thereby, consisting in supporting thelatter in unyielding position upon the former durin the grindingoperation.

2. The metho of truing and grinding the surfaces of two adjacent partsof the same structure, one of said parts being relatively rigid and theother yielding, consisting in supporting the latter in unyieldingposition .upon the former by means of a readily-fusible substance duringthe truing and grinding operation.

3. The method of grinding packing-rings, consisting in placing the samein the grooves in the member in which they are to remain, introducingareadily-fusible substancein the grooves under the rings, applying thememton, and supporting said rings unyieldingly in such position duringthe grinding operation. I

.IIO

5. The method of simultaneously grinding I In testimony whereof I havesigned my a piston and its packin -rings, consisting in name to thisspecification in the presence of centering and fixing. sai .rings intheir places two subscribing Witnesses. on the piston'with theirsurfaces'fiush With. v PAUL GAETH. 5 the surface of the piston, andholding said Witnesses: 1

rings in said'position unyieldingly during the JOHN A. BOMMHALRDT,grinding operation. ANDREW GRIEBEL.

